Key Concepts: The somatic neuromuscular junction is the site of communication between motor neurons and skeletal muscle fibres. Specialisations of the neuromuscular junction mean that activity in and release of transmitter from motor neurons produces contraction of skeletal muscle fibres rapidly and reliably.he neuromuscular junction comprises four cell types: the motor neuron, terminal Schwann cell, skeletal muscle fibre and kranocyte, with the motor neuron and muscle fibre separated by a gap called the synaptic cleft.
Causes. Headaches can be triggered by a variety of factors. The most common cause of headaches is prolonged tension or stress. These are called tension headaches or muscle-contraction headaches. Virtually everyone suffers from this at some time. Muscles in your scalp, neck, and face tighten and contract, causing spasms and pain.
The most common types of headaches are: Tension headaches: Also called chronic daily headaches or chronic non-progressive headaches, tension headaches are the most common type of headaches among adults and adolescents.These muscle contraction headaches cause mild to moderate pain and come and go over a prolonged period of time.oth adults and children experience this type of headache. Cluster headaches: The least common -- although the most severe -- type of primary headache, the pain of a cluster headache is intense and may be described as having a burning or piercing quality that is throbbing or constant.